Madison, Wisconsin – Scientists at the UW are working to answer the questions many women ask about: why they developed cancer.

UW Carbone Cancer Center researchers have begun a five-year project to study how exposure to certain environmental factors during three phases of a woman's life may affect her risk for developing breast cancer. Cancer survivors themselves helped guide the questions about diet, environmental toxins and other exposures that the study will investigate.

The Breast Cancer and the Environment Research Program (BCERP), a joint effort funded by the National Institute for Environmental Health Sciences and the National Cancer Institute, has awarded a $445,000 five-year grant to researchers Dr. Michael Gould and Dr. Amy Trentham-Dietz, to conduct the study of these "windows of susceptibility."

Gould, a professor of oncology at the UW School of Medicine and Public Health (UW SMPH) will conduct research using rat models. Gould is based at the McArdle Laboratory for Cancer Research and is an expert on breast cancer genetics. Trentham-Dietz, associate professor of population health sciences at UW SMPH, will compare the results of the rat-model research to archived DNA of more than 7,000 Wisconsin women.

"Our community partners have helped us shape this research to understand what women are concerned about, and what questions they would like us to research," says Trentham-Dietz, a cancer epidemiologist.

Past research has shown that the impact of environmental factors on breast cells is highly dependent on the breast’s physiological and developmental status at the time of exposure. For example, Japanese women who were exposed during puberty to high levels of radiation from atomic bombs during World War II showed higher rates of breast cancer when they reached their 50s and 60s than women who were not exposed.

Researchers will look at three of these windows of susceptibility, which coincide with hormonal landmarks in a woman's life. The windows are childhood (three-week-old rats); adolescence (seven-week-old rats); and peri-menopause (65-week-old rats).

The scientists hope to determine if several environmental factors previously shown to influence breast cancer susceptibility when introduced at adolescence extend to the childhood and older-adult windows.

Community partners - including the Wisconsin Breast Cancer Coalition and Susan G. Komen for the Cure, Madison affiliate, Wisconsin Cancer Council and the UW-Milwaukee College of Nursing Institute of Public Health - have given input to the researchers on the factors women want to see investigated. They include diet, indoor and outdoor chemicals, occupational exposures and chemicals in water.

The partners also will communicate results of the research and how women can use it to decrease their risk of breast cancer.

"The community partners plan to provide the Wisconsin community with some of the clear evidence-based messages that come out of research. BCERP research should allow us to understand additional causes of breast cancer and to bring information that ultimately can assist people to make choices that can limit their risk of breast cancer. Prevention is the ultimate goal," said Mary Pat Berry, of the Madison Affiliate of Susan G. Komen for the Cure.

The Wisconsin project is one of eight BCERP-funded studies on windows of susceptibility across the country. Researchers from all sites will meet regularly to discuss findings, and that collaboration is an exciting development for breast cancer research, Trentham-Dietz said, adding, "Bringing experts together can really move research forward faster."